I recently purchased a 320 X Compact (I am in LE and carry a 320 Carry for duty) and I want to get a romeo sight to put on top of the X Compact. Anyone who has already, which romeo model did you go with? Would you recommend that model? And what is the backup irons situation(need iron in case of electronic failure during duty use)? The groove on the romeo sufficient or do you need to install the rear sights somehow?